The way life began on Earth continues to impress scientists, but going back billions of years into the past is not easy.
And now there is more and more evidence regarding a new hypothesis about how life began: with a very precise mixing of RNA and DNA.
Both RNA and DNA determine the genetic makeup of all biological life, with DNA serving as the genetic blueprint and RNA as the reader or decoder. It was long believed that RNA first evolved on Earth and then DNA, but a growing body of evidence suggests that they appeared at the same time and both were involved in the origin of life on this planet.
A 2021 study supported this idea by explaining how the simple compound diphosphate (DAP), which may have predated life on Earth, can bind DNA building blocks called deoxynucleosides in DNA backbones.
“This discovery is an important step towards developing a detailed chemical model for the emergence of the first forms of life on Earth,” said chemist Ramanarayan Krishnamurthy of Scripps Research in California in January 2021.
The findings support the idea that DNA and RNA emerged together through chemical reactions of the same type during early life on our planet, and that the first self-replicating molecules could be a mixture of these nucleic acids, and not just RNA, as proposed in the hypothesis. .The most established “RNA world”.
One big problem with the idea that RNA alone gave rise to life on Earth is how RNA can go through the necessary process of self-replication – RNA usually requires cleavage enzymes that evolved after RNA.
From what we know so far, RNA appears to have been of some help in engineering life—recent experiments have shown that DNA can, by creating “chimeric” molecular strands that can separate more easily than RNA alone.
A series of researchers’ lab tests mimic what happened before life began on Earth, showing how DAP could form the core of DNA in the same way that RNA can be assembled from chemical building blocks.
We may not know for sure whether RNA DNA helped create the first life forms on our planet, given that it happened billions of years ago, but our understanding of these processes continues to evolve.
Not only is the study useful in terms of how it relates to the origin of life, but understanding the relationship between RNA and DNA could have a range of applications in modern chemistry and biology.
The search was published in Angevante Hemi.
Source: Science Alert.